$(\Delta H - \Delta U)$ for the formation of carbon monoxide $(CO)$ from its elements at $298 \ K$ is ............. $J \ mol^{-1}$. $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$

When a gas undergoes adiabatic expansion,it cools down because:

When $1 \ mole$ of gas is heated at constant volume,the temperature rises from $273 \ K$ to $546 \ K$. If heat supplied to the gas is $x \ J$,then find the correct statement from the following.

For an isochoric process,the first law of thermodynamics can be expressed as:

What is the change in internal energy if a system gains $x \ J$ of heat and $y \ J$ of work is done on it?

$C_2H_5OH(l) + 3O_2(g) \rightarrow 2CO_2(g) + 3H_2O(l)$. The enthalpy change $(\Delta H)$ for the above reaction at $27^{\circ}C$ is $-1366.5 \text{ kJ mol}^{-1}$. Calculate the internal energy change $(\Delta U)$ for the same reaction at this temperature.